OBN:
You will also find, worldwide, a severe lack of obstacles in the survey. Even in the US, the Part 77 surfaces are limited, and there is no proactive effort to gather obstacles. (note that SafeCo Field was built in the flightpath for Boeing Field, and wasnt even lit. It was the Head of the FAA flying in for a meeting, that wondered about this huge dark spot in the middle of the City)
As you certainly know, Part 77 is not designed to provide OEI surfaces. It's up to the operators to provide each runway end OEI survey up to the OEI en route flight path.
In most other Countries, it is even worse.
Indeed it is as to "normal ops" obstacle data. But,
no country has obstacle data for OEI.